Radio apparatus



July 29, 1952 E. F. ANDREWS RADIO APPARATUS Filed Nov. 25, 1945 RN NRNNBNX NMQHMNYNQN WJ N ,M di w w m/m d A l N wr @la w J k m? wml QQ Qa @w Q QM, M j Tw A@ w W W Il l: NQ Nhh M mmf Y ...AM/www .d m Hm Nm, 2 ww A@ @a 1w. @l m m ANR m w E M Patented July 29, 1952 RADI() APPARATUS Edward F. Andrews, Chicago, Ill., assigner to Signal Tuned Radio Corporation, Chicago, Ill., a corporation of Illinois Application November 23, 1945, Serial No. 630,193

(Cl. Z50-20) Claims.

The present invention relates to radio appa ratus `and more particularly to radio apparatus of the type energized from a low voltage direct current power supply and including motor operated means. The invention has for its primary object the provision of a new and improved apparatus of 4this type employing an alternating current motor and translating means for supplying the motor with alternating current from the direct current power source.

Another object of the present invention is to provide a radio apparatus having new and viinproved `motor operated tuning means and volume control means, and more specifically, a stop-oncarrier type radio receiver having a new and improved battery energized alternating current motor for operating both tuning and volume Acontrol means.

Another object of the present invention is `the provision of new and improved radio apparatus including an alternatingv current motor supplied with .power from a battery through means including a circuit interrupter, such as a vibrator,

supplying power also to other elements of the radio apparatus.

Another and more specific object of the invention is the provision of new and improved radio apparatus including an alternating current capacitor type induction motor rhaving an induction rotor for driving an element or elements of I'the radio'apparatus, such as tuning or volume control means, and wherein said motor is sup- .pliedwith a relatively high alternating current voltage Yfrom a battery by translating means preferably .including a circuit interrupter and a step-iup transformer, whereby a smaller, and

therefore less expensive, capacitor may be used.

A further object of the present invention is ,the provision of a new and improved radio receivernf the type including volume control means and tuning means wherein said control means are Yselectively operated by a single alternating current ymotor of the induction type supplied with alternating current from a power source supplying the receiver elements with direct current plate voltage. An induction type motor, i. e. one having no commutator, or which is non-commutating during normal operation, creates no undesired electrical disturbances during operation with the result that the volume control means, especially, may be operated without interfering with the quality of reception. Shielding of the motor is also rendered unnecessary.

A further object of the present invention is to Cil provide an apparatus of the character set forth in the preceding paragraph in a stop-on-carrier type radio receiver, whereby the tuning means may be operated and stopped to tune in stations in an eilicient manner because of the elimination of undesired disturbances which would interfere with the operation of the stop-on-carrier tuning means.

Other objects and advantages of the present invention will become apparent from the ensuing description of an embodiment of the invention,

f in the course of which reference .is had to the raccompanying drawing, the single dgure of which schematically represents a stop-on-carrier type of radio receiver constructed in accordance with the invention. f

The present invention is embodied in a radio receiver which has not been illustrated in detail and which may take various forms. For instance, it may be, and has been illustrated as being, of the stop-on-carrier type disclosed and claimed in the copending application of William J. OBrien, Serial No. 605,397, iiled July 16, 1945 (Patent No. 2,569,426). The receiver, which is indicated as a Whole by reference character III, has associated with it an antenna I2, tuning means I4 and volume control `means I6 associated with electron tube amplifying means, sound reproducing means, such' as a loud speaker I8, and a stop-on-carrier tuning control relay 20. The relay is preferably so constructed and arranged that it s'energized, and in what may be termed an operated position, during the tuning operation and is deenergized and returned to a non-operated position when a station is tuned in. Various means are operated by the relay and in so far as an understanding of the present invention is concerned, it is desired to point out that among these are a motor circuit control switch 22 and clutch means illustrated diagrammatically and indicated as a wholeby reference character 24.

In accord-ance with the present invention, the apparatus ls supplied with power from a suitable low voltage direct current power source such as a battery 30, which may be the battery present in an automobile or aircraft, supplying power to the relay 20 and the filaments of the tubes of the receiver and rectifier and also supplying direct current voltage to the plates of the various tubes included in the apparatus through suit able translating means producing a current Awith an alternating current component. The translating means is preferably, but not necessarily, of the type including a vibrator indicated gen- -winding 4S associated with the Vibrator.

erally by reference character 32. However, a rotary type circuit interrupter or an invert-er could be used. rIhis translating means, in accordance with one of the important features of the present invention, is utilized to supply alternating current Voltage to an alternating current motor 34 of the induction type, and preferably of a type which is non-commutating during normal operation, operatively connected to the tuning and volume control means through the clutch 24 in a manner which will be described in greater detail shortly. The elimination `o1" a commutator and brushes from the motor permits use of a motor which Ais much smaller and cheaper as well as one that does not cause any extraneous electrical interference.

In order to eliminate disturbances in the direct current power supply, the battery is connected to the vibrator through a nlter system including the two series connected choke coils 35 and the three capacitors 38 connectingr the terminals of the choke coils to ground.

The vibrator type power supply system supplies the requisite alternating current voltage to a plate rectifier and lter system indicated as a whole by reference character 4S. The plate voltage is supplied to the radio receiver elements, such as electronic amplifying means, through a conductor 42. The rectifier is supplied through a secondary7 winding 44 forming part of a transformer indicated as a whole by reference character 46 and including a center tapped primary The battery is connected to the center tap of pri mary winding through a conductor 50.

The vibrator includes a magnet 52 operating a vibratingT reed 54 in known manner alternately to connect the two halves of the primary winding 48 across the battery thereby to induce an alternating voltage in the secondary windings of the transformer.

As alreadyT indicated, one of the important features of the present invention resides in the utilization of alternating current derived from the translating means to energize the alternating K current induction motor 34, which is preferably a reversible capacitor type motor-although other types oi motors, such as split phase motors with resistance and inductance in circuit with the motor windings could be used. The motor is sup- .f

plied with alternating current voltage, and preferably high voltage in order that the capacitor 56 associated wtih the motor windings may be made smaller and therefore less expensive. The motor includes, for example, a stator 58 having iour poles, the opposite ones of which are surrounded by the two motor windings 6! and B2. One terminal of each winding is connected by conductor 63 to a first terminal of a secondary winding G4 associated with the translating means and in which a high voltage alternating current voltage is induced. A ibuer capacitor 66 is connected across the terminals of the secondary winding. The second terminal of the winding is connected to ground through a conductor G3 through which motor energizing circuits are completed in a manner which `will appear shortly.

It is possible to use a low voltage motor, in which case the step-up ratio of the transformer could be lowered or the secondary winding 64 even 'h dispensed with and the motor connected directly to the interrupted primary circuit. However, if this latter is done, the capacitor 56 must be a large one and should be of the back-to-back electrolytic type. rhe use of an additional secondary winding B4, however, is preferred because it minimizes interference which might be fed into the receiver if the motor was connected to the primary and, also, because it does enable a higher voltage to be used.

It is contemplated also that the alternating current supplied te the motor be of a relatively high frequency, such as about 100 cycles or higher. At frequencies of this order a small motor, such as would be employed in apparatus of the character under consideration, can be constructed more economically and will have a higher eiciency. This is especially desirable as any increase in the wattage required by the motor increases the load on the interrupter contacts.

The motor is adapted selectively to be connected to the tuning and volume control means to adjust them. It should be understood, hown ever, that the motor could be utilized to operate only one of these means, e. g., the tuning means. The motor rotor 10, which is of the induction type, and may be a squirrel cage rotor, is connected to a clutch i2 of a type adapted to be engaged whenever the motor is energized and disengaged whenever the motor is deenergized.

The motor and clutch 12 are adapted selectively to be connected to the tuning means I4 or volume control means I6. The motor is connected to the volume control means at all times except when the tuning means is being operated, and it is shown so connected to the volume control means in the drawing. The connection to the volume control means is effected through a clutch 14 and the connection to the tuning means is effected through a clutch 16. The arrangement is such that when one of the clutches is engaged, the other is disengaged.

The engagement of clutches 14 and 'I6 is under the contro] of the stop-on-carrier relay 20. When the relay is deenergized and in its non-operated position, the volume control clutch 14 is engaged, When the relay is energized and in its operated position, which it is during the tuning operation, the clutch T6 is engaged. When the tuning operation is completed under the control of the stopon-carrier control, the clutch 'I6 is disengaged and clutch 14 again engaged.

When the volume control clutch 14 is engaged, the volume controlling means may be operated to increase or decrease the volume by the user. The operation is controlled by a manually operable switch 80 forming preferably a part of a remote control unit indicated as a whole by reference character 82. This remote control unit would be located at a place where it would be readily accessible to the operator of the vehicle which, as heretofore indicated, may be an automobile, airplane, etc. The remainder of the apparatus can be constructed as a unit and this is the way it would be ordinarily built. The switch is operable from neutral into one position to energize motor 34 for rotation in one direction and into another position to energize the motor for rotation in the opposite direction. The direction of rotation is controlled by the connection of capacitor 56 in series with one or the other of the motor windings 60 and 62.

To operate the motor in one direction. say in a direction to increase the volume, the switch is operated to connect the capacitor in series with winding Sii. In this position the switch connects the winding Si! and capacitor 56 in series across the secondary winding 64 of transformer 46. The circuit extends from the transformer through conductor 53 to the windings and capacitor and thence to the other side of the transformer through conductors 86, 86, the switch blade 60 completing the circuit with conductor 88, ground connection 90 of the switch and the previously referred to ground connection 66. In this position of the switch the motor winding 62 is connected directly across conductors 63 and 66 and thus across the secondary winding of the transformer. In orderto operate the motor in the volume decreasing direction, the switch is operated to complete' a circuit through conductor 92, thereby placing the capacitor 56 in series with winding 62 and connecting winding 60 directly across the secondary winding.

The stop-on-carrier control includes means forming part of the control unit for placing the tuning means in operation to select another station.. This means includes, as fully set forth inthe previously referred to copending application of William J. OBrien, a manually operable switch 94 operable to complete a circuit to the relay whereby the relay is energized and moved to its operated position. This circuit includes the conductors 96 and 96 through which a relay winding, not shown, is adapted to be connected across the battery. Conductor 98, it may be noted, is connected to the battery throughv a portion of the filter system. Conductor 96 leads to a contact associated with switch 94 and the latter is connected to ground through conductor |00 and the previously referred to conductor 90. When the switch is closed, the relay winding is energized through conductors 96 and 96 to operate the clutch and to place the tuning control apparatus into` operation. The tuning means is operated by motor 34 as long as switch 94 is closed and the motor will continue to operate after the switch is opened because the armature of the relay which operates motor circuit control switch '22 is held in closed magnetic circuit position by the residual flux. When a signal is tuned in bythe tuning means |4, a voltage is impressed on the grid of an electron tube coupled to the relay. The change of plate current in the electron tube produces a current surge in the relay opposing the holding flux, releasing the armature and moving the motor circuit control switch 22 and associated mechanism to motor stopping position, as described more fully in OBrien Patent No. 2,426,580, previously mentioned.

When the tuning means I4 is being operated, the motor 34 is automatically reversed at the limits of movement of the tuning means by an automatically operable motor reversing switch |02 operable into two positions. In the two positions the circuits are completed through conductors 88 and 92 so that, as previously described, the capacitor 56 is placed in series with one or the other of the windings to effect rotation of the motor in opposite directions.

When the tuning means is operated, the energizing circuit for the motor is completed not only through the reversing switch |02 but also through the previously referred to motor circuit switch 22 adapted in one of its two positions to connect the switch blade |02 to ground through conductors |04 and |06. The switch blade 22, like the clutch means 24, is operated by the stopon-carrier relay and it is moved to complete the circuit to the reversing switch only during the time the tuning means is being operated by the motor. It might be mentioned that the switch 22 is also used to control operation of the stopon-carrier control through means including a conductor |08 which is connected to ground when the stop-on-carrier relay is in its non-operated position, but inasmuch as this control forms no part of the present invention, it has not beenv illustrated nor will it be described in detail.

In operation, power is supplied to` the apparatus from the battery- 30, which supplies klow voltage direct current tovarious elements of the radio apparatus and to the vibrator type power supply for supplying the requisite alternatingl the volume control or stop-on-carrier tuning means is beingr operated. -Itis alsopreferred, as indicated above, thatv the motorgbe of the' capacitor type and that,thetsecondarywinding 64 supply a relatively highjvoltage so that the size of the capacitor 56 may be reduced. Accordingly, a smaller and less expensive capacitor may be used and it should be noted alsothat the capacitor may be of the back-to-back electrolytic type because it is used only intermittently..

Also, no shielding is required.

In order to vary the gain of the radio receiver, or the volume, the switch is operated to complete a motor energizing circuit through one oi conductors 88 or 92 therebyto operate the motor in opposite directions to vary the volume as desired. The motor does not create any extraire-- ous disturbances during its operation which would adversely affect the reception because it has no communtator interrupting electrical circuits, so that even though the set is not muted, as

it is not during adjustment of the volume control means, the operation of the motor producesl no audible sound in the output of the speaker.`

When it is desired to change the tuning of the receiver, the switch 94 is closed toplace'the stopon-carrier tuning means into operation 'byenergization of Ythe relay. The latter operatesl theclutch 24 to disengage `thevolumecontrol clutch I4 and to engage the tuning meansr kc1utch"|6;"`At the same time the switch 22 ,is moved to complete a circuit to ground `from the reversing switch |02.

The tuning means is changed by the motor inone direction or the other, depending upon thefposition of the reversing switch |02, either as long as the switch 94 is closed or until the relay is deenergized in response to the tuning in o f a sta-` tion after the switch has been opened. Here` again the use of an induction motor is oficonsiderable advantage because itcreatesnoex-Y traneous electrical disturbances whichwould effeet operation of the stop-on-carrier control rat undesired points or times.

While but a single embodiment of the invention has been described in detail, it should be understood that the details thereof are not to be construed as limitative of the invention except insofar as set forth in the accompanying claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, a radio receiver having a variable tuner, a low voltage battery, a transformer having a primary and two secondary windings, an automatic circuit interrupter, means including an interference iilter connecting said battery, said interrupter, and said primary in series, means for varying said tuner including an alternating current induction motor, a switch connecting said induction motor to one of said secondary windings, radio amplifying means including a plurality of electron tubes having grids, plates, and laments, rectifying means connected to said other secondary winding and to the plates of said tubes, means connecting said filaments to a part of said battery ,circuit isolated by said iilter from said interrupter, signal reproducing means coupled to one of said plates, means coupling said tuner to one of said grids, means for manually operating said switch to start tuning, and means for automatically operating said switch to tune in and reproduce a desired signal.

v2. In combination, a radio receiver having a variable tuner, a low voltage battery, a trans# former having a primary and two secondary windings, an automatic circuit interrupter, means including an interference lter connecting said battery, said interrupter, and said primary in series, means for varying said tuner including an alternating current induction motor connected to one secondary winding, radio amplifying means including a plurality of electron tubes having grids, plates, and filaments, rectifying means connected to the other secondary winding and to the plates of said tubes, means connecting said laments to a part of said battery circuit isolated from said interrupter by said filter, signal reproducing means coupled to one of said plates, means coupling said tuner to one of said grids, and means for manually starting and automatically stopping said motor to tune in and reproduce a desired signal without tuning motor interference.

3. In combination, a radio receiver having a variable tuner and a variable Volume control, a low voltage battery, a transformer having a primary and two secondary windings, an automatic circuit interrupter, means including an interference filter connecting said battery, said interrupter, and said primary in series, means for alternatively varying said tuner and said Volume control including an alternating current induction motor coupled to and deriving its power from onesecondary winding, radio amplifyingmeans including a plurality of electron tubes having grids, plates, and filaments, rectifying means connected to the other secondary winding and to the plates of said tubes, means connecting said filaments to a part of said battery isolated by said filter, signal reproducing means coupled to one of said plates through said volume control, means coupling said tuner to one of said grids, means for manually starting and automatically stopping said motor to tune in a desired signal, and means for disconnecting said motor from said tuner and connecting it to said volume control to control the volume of reproduction when said signal is tuned in.

4. In combination, a stop-on-carrier radio receiver having a variable tuner, a low voltage battery, a transformer having a primary and two higher voltage secondary windings, an automatic circuit interrupter, means including an interference filter connecting said battery, said interrupter, and said primary in series, means for varying said tuner including an alternating current induction motor connected to and deriving its power from one of said secondary windings, means for stopping said tuner including a plurality of electron tubes having grids, plates, and laments, rectifying means connected to said other secondary winding and to the plates of said tubes, a relay having contacts which when open disconnect said one secondary winding from said motor, means coupling the plate of one of said electron tubes to said relay, means connecting said filaments to a part of said battery circuit isolated from said interrupter by said filter, and means supplying a signal tuned by said tuner to the -grid of said one electron tube to operate said relay and stop said tuner.

5. In combination, a stop-on-carrier radio receiver having a variable tuner, a low voltage battery, a transformer having a primary and two secondary windings, an automatic circuit interrupter, means "including an interference lter connecting said battery, said interrupter, and said primary in series, means for varying said tuner including an alternating current induction motor coupled to and deriving its power from one secondary winding, means for stopping said tuner including relay means and a plurality of electron tubes having grids, plates, and filaments, rectifying means connected to said other secondary winding and to the plates of said tubes, means coupling the plate of one of said electron tubes to said relay means, means connecting said filaments to a part of said battery circuit isolated from said interrupter by said filter, and means supplying a signal tuned by said tuner to the grid of said one electron tube to operate said relay means and ystop said tuner.

EDWARD F. ANDREWS.

REFERENCES CITED The following references are of record in the le o this patent:

UNITED STATES PATENTS Number Name Date 1,935,569 Keogh Nov. 14, 1933 2,098,331 Bowman Nov. 9, 1937 2,112,687 Barton Mar. 29, 1938 2,326,737 Andrews Aug. 17, 1943 2,369,542 Dietrich Feb. 13, 1945 

